BACKGROUND: Patients to require total hip replacement (THR) or total knee replacement (TKR) are at high risk of developing post-operative deep vein thrombosis (DVT) and pulmonary embolism (PE), known as venous thromboembolism (VTE)[1,2]. An anticoagulant prophylaxis is recommended, low molecular-weight heparin is mostly used[3].OBJECTIVES:  Determinate cost-effectiveness of apixaban in VTE prevention (VTEp) after THR or TKR in adults from perspective of Costa Rica’s Public Health System (CCSS). METHODS:  A tree-decision-model (short-term) and markov-decision-model (long-term) were designed using clinical trials data (effectiveness and clinical events) to evaluate lifetime costs and quality-adjusted-life-years (QALYs) of apixaban (2.5mg BID) in comparison of enoxaparin (40mg/day). CCSS used only enoxaparin as VTEp.  A cohort of 1000 hypothetical patients with initial age for THR and TKR respectively are:  65 years and 71 years average[4].The distribution of surgery is 51% THR and 49% TKR[4]. The patients were introduced and distributed each therapy to analyze the probability of suffering clinical events. The horizontal time is 90 days (short-term) and 5 years (long-term) before surgery. The clinical events evaluated are: total VTE events (PE, distal and proximal DVT) and total bleedings events (Intracranial Hemorrhage, non-major clinically relevant, Major and Minor bleeds) in the short-term; VTE event and post thrombotic syndrome (PTS) in long-term. Costs were obtained from databases of CCSS[5,6]. Sensitivity analysis was also performed and 5% discount rate. RESULTS: The events present for 1000 hypothetical patients (51%THR/49%TKR) short-term are: 68 vs 118 total VTE and 72 vs 83 total bleeds (apixaban vs enoxaparin); in large term are: 20.6 vs 35.8 total VTE and 18.8 vs 32.6 PTS (apixaban vs enoxaparin). Overall costs and QALY per patient are: US$542.53 and 4.9587 QALY for apixaban; US$740.82 and 4.9479 QALY for enoxaparin. CONCLUSIONS: Apixaban is cost-saving therapy for VTE prevention compared to enoxaparin after THR or TKR in the social security of Costa Rica.